稀土元素對Sn-3Ag-0.5Cu-4Ti活性軟銲填料合金氧化行為之影響

Abstract

In this study, the effects of trace addition of rare earth elements on the oxidation behavior of Sn-3Ag-0.5Cu-4Ti active solder were investigated in air at 200 and 250 °C. Addition of a trace amount of rare earth elements into active solder resulted in decreasing the oxidation rate of the solder at 200 °C. The oxidation rate increased with increasing the amount of rare earth elements in the solders. The active solder containing 0.05 wt.% rare earth elements showed the best oxidation resistance. After oxidation in air at 250 °C under the solder melting condition for 1008 hours, a less than 1.5 μm thick TiO oxide layer formed on solder. Doping concentration more than 0.2 wt.% rare earth elements, the oxidation rate increased significantly with the amount of the rare earth elements. After an exposure time of 1008 hours in air at 250 °C, the oxide layer formed on the 0.5 wt.% rare earth elements containing active solder was 6 times the thickness of the 0.05 wt.% rare earth elements containing solder.